What it means for your advertising
It's usually a small tag or pixel from the platform, placed on your site, that fires when someone submits a form or reaches a thank-you page. Calls work differently: on Google, the ad shows a forwarding number, and Google counts a call to it as a conversion. The platform uses all of these to count conversions and to learn which people are most likely to convert.
Tracking that uses cookies needs consent under UK privacy law, so it should sit behind your cookie banner. Missing or broken tracking is a common reason a campaign reports clicks and no results.
An example
Java Roasters' enquiry form leads to a thank-you page. A tag on that page records a conversion each time it loads, so the campaign can tell the 10 enquiries apart from the 230 visits that didn't enquire.
Java Roasters is a fictional business, and its figures are illustrative.
How we handle it
We help you set up tracking through Google Tag Manager, and check it works before your campaign goes live. Calls from your Google ads are tracked with Google's forwarding numbers. Our guide to tracking your ad enquiries walks through the setup.